A secret operation has succeeded in capturing another bin laden. This time, the son-in-law. He has been brought to the united states. So, how did they find him? And what is he saying tonight? Abc's chief investigative correspondent, brian ross, has been reporting the story all day. Reporter: In the world of al qaeda, he was the guy who married the boss' daughter, which gave him a place of prominence next to osama bin laden. But sulaiman abu ghaith never took over the family terror business and became better known as the loudmouth son-in law -- the al qaeda spokesman who proclaimed his delight in this video over the 9/11 attacks on the united states. There wasn't even a reward posted for the son-in-law on the u.S. Rewards for justice terrorism webse. But the cia has been tracking abu ghaith for years, according to u.S. Officials, as he moved first from aftghanistan to iran and then, in january, into turkey, where he was arrested based on a u.S. Tip. Once he left iranian territory and got into turkey, with very close monitoring by u.S. Government agencies, he was -- his days were numbers. Reporter: The turks then sent him to jordan, where, before being sent to new york, officials tell abc news the significance of his capture became apparent, as he revealed new details on the current status, personnel and finances of al qaeda. This is a man in the inner circle of bin laden's al qaeda operations and now we have him alive and he's talking. Reporter: Growing up, bin laden has made the family targets wherever they go. In the 2011 u.S. Raid on bin laden's hideout in pakistan, at least one son was killed. A second son had been killed in an earlier drone strike. Abu ghaith is already in the u.S. And will appear before federal magistrate here in new york tomorrow morning. An indication he'll be put on public trial, not before military judges in guantanamo. Facing charges of conspiracy to kill u.S. Citizens. Diane? Brian, thank you so much.

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